iS6 



of itself to set up disease, independentl}^ of the help 

 of egg food at all, in some races or in some individuals 

 of other races of birds, provided that it is vigorous 

 and plentiful, and that it meets with a lowered power 

 of resistance in the individuals it attacks. Absoluteh^ 

 immune individuals will repel the bacillus and 

 destro}^ its toxins w^ith or without egg food. But why, 

 by means of the agency of egg food, should we assist 

 the bacillus to destroy those birds which, while not 

 altogether immune, w^ould have been able without it 

 to have successfully resisted? Why, when a battle 

 is raging between the phagocytes of our birds and 

 the invading bacilli, should we step in and supply 

 the enemy with just those munitions of war which 

 enable it to trail our own flag in the dust ? 



An incident that happened in the bird-room of 

 one of the members of the Foreign Bird Club in May, 

 1902, affords a very pertinent commentary on what I 

 have just said. During that month, so I am informed 

 by this lady, she lost over fifty Canaries that were in 

 her breeding cages at tlie time, and that were being 

 fed according to the usual custom on egg food. In 

 telling me this she goes on to sa}' : — " One very 

 " strange thing happened ; all the time ni}^ Canaries 

 *' were dying I had in the same room an aviary full of 

 " foreign birds and I never lost one of them." In 

 a subsequent letter she tells me that she never gave 

 the foreign birds an}' egg food at au}^ time, and that 

 all they ever had in addition to their staple food of 

 canar3% millet, and rape seed, was an occasional meal 

 of ants' eggs and oats. 



Now what was the determining cause that led to 

 the exemption of these birds from infection? That 

 the germs of the disease were carried to them must 

 be beyond doubt. They permeated the air of the 

 room ; they swarmed in the seed tins, in the rinsings 

 of the water vessels, in the dusters and brushes, and 



